


The Blue Spectrum

by Komyxans



Category: Undertale (Video Game)
Genre: Fluff, Hurt/Comfort, Implied Relationships, Multi, One Shot Collection, Slice of Life, Spoilers, Takes place in a Pacifist Run, lots of fluff, reader is frisk if you want it to be
Language: English
Status: In-Progress
Published: 2015-12-05
Updated: 2015-12-11
Packaged: 2018-05-05 04:06:06
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 2,842
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5360690
Author URL: https://archiveofourown.org/users/Komyxans/pseuds/Komyxans
Summary: <blockquote class="userstuff">
              <p>All these shades of blue represent Sans’ soul. A collection of oneshots about this skeleton’s life and everything that happens around it.</p>
            </blockquote>





	1. Aquamarine

**Author's Note:**

> Hey, reader! I’ve had this idea about writing this for some time now since I love both writing oneshots and writing about Sans. The chapters might be loosely connected but most of them can be read on their own without missing big pieces of information. There are/will be some implied ships such as Alphys&Undyne and Sans&FallenHuman/AdultFrisk/Reader(?). Check the tags for an updated version of the list.
> 
> I also tried to keep the human gender-neutral, but I’m not used to writing like that. I’m sorry if I used a gender-specific pronoun for them in any of my chapters!
> 
> (Oh, and every chapter will be named after a type of blue!)
> 
> Hope you enjoy!

“Do you come here often?”

Sans swiftly turned around to find the human standing behind him, giving the skeleton a curious look. Sans’s eye sockets widened in shock. How did they sneak up behind him? And how did they manage to discover this place? This part of the Waterfall cavern was not well-known among monsters. But of course the human was… well, human. Perhaps they were just gifted at finding secrets. 

The area that the two were in was unique, to say the least: it consisted of a relatively small platform, surrounded by pointed rocks and a canyon reaching far into the depths of the Underground. That’s most likely what made everyone uncomfortable, Sans guessed. Even Papyrus had been reluctant to join him here. 

However, the reason that Sans loved to visit this place was because of the unobstructed view of the luminous ceiling. The stunning aquamarine glow was wonderfully soothing to Sans, but not in a way that he would fall asleep. He came here because he wanted to experience every second of the shimmering rocks.

For a moment, Sans forgot to reply to what the human said but he quickly recovered.

“that’s a pretty weak pick-up line, you know.”

The human giggled before coming closer. They stopped next to where Sans was sitting, which was on a big, flat boulder. “May I join?”

“sure, kid,” he answered, gesturing to the empty space beside him. They sat down carefully and smiled back at the skeleton. 

“so what’s up?” Sans asked, still wondering why the human came up here.

“The ceiling, of course,” the human said before bursting into laughter. It was likely the lamest, most overused response to that question ever. It was perfect to Sans, and he laughed along. Inbetween the chuckles, the human tried to continue their story. “B-but seriously, this place is beautiful!”  
The human paused to admire the glistening ceiling for a minute. Sans stared at the human instead, interested in their reaction.

“yeah, it is.”

“I mean, you can see so much from here. They remind me of the stars at home…” Their voice trailed off, their gaze still fixed to the glowing ore above. 

No one said anything for a couple of minutes. It was a good type of silence; neither of them felt forced to say anything. Together with the pleasant warmth that emitted from the human sitting close to him, Sans felt remarkable comfortable. They sat together in silence for a while until his curiosity made him speak up again.

“i wonder what the real stars on the surface look like. i’ve actually read all about them.”

“Really?” They smiled in disbelief, “You read?”

“nah, i only look at the pictures,” Sans mentioned as if it were a joke, but they both knew he was being completely serious. The human replied with goofy grin. He continued: “but pictures don’t capture the same feeling as when you’re looking at something in real life.” 

“Yeah,” the human agreed, “I always used to watch the night sky if I couldn’t sleep. I saw a falling star once.”

“really?” The skeleton’s bones rattled in fascination. “what is it like?”

“It’s a giant rock flying through space. They travel so fast that they are on fire. Cool, huh?” the human explained. They stopped to think while Sans was still actively attempting to process the information. “Now that I think about it… although they call it a falling star, it is not actually a star.”

Sans was left with millions of questions in his mind. So they talked about the stars, the sun and even about humans that went to space. Sans, like many monsters, had heard of space before but the human clearly had much more knowledge on the subject. He’d love to see the stars and the rest of space someday. It seemed magical, and that statement was coming from a monster.

“wow,” he breathed and winked, “that really is 'out of this world'.”

They both laughed loudly yet another time. Eventually, it died down and it became so quiet that Sans could hear the water splashing in the nearby river and the pebbles falling into the depths of the enormous canyon in front of them. The realisation of where he was kicked in again. In the meantime, his eyes shifted from twinkle to twinkle. 

“will these ‘stars’ beat yours, the ones on the surface?”

The human looked slightly confused as to what Sans asked. “What?” they questioned, more curious than anything.

“well-“ he started, “you’ve just told me about space and it sounds like it’s amazing. these things here are just plain rocks.”

Their curious expression turned into a thoughtful frown. “Stars are great and all, but we certainly don’t have glowing rocks on the surface. I believe both kinds are beautiful in their own way. Maybe I even like these ‘stars’ better. It all comes down to how you appreciate it.”

“funny that you say that,” Sans chuckled, closing his eyes, “i’ve always liked the glowing rocks of the Waterfall because of their colours. they shine all kinds of blue... it’s a different blue every day.” When Sans opened his eye, a faint blue glow emitted from his left eye socket that was staring right into the human’s eyes. Similar to the rocks, the iris flickered slightly, changing its blue nearly every second. The human’s eyebrows raised in surprise since they had never seen this before. The short skeleton smiled gently. “it’s like my soul. i also feel different every day. the idea just… makes me happy.” He sighed, looking away into the distance. “I may also like these ‘stars’ better because of that. i don’t know if that makes any sense to you. probably not.”

A head began leaning against Sans’ shoulder, which startled him and caught him off guard. “That makes perfect ‘sans’ to me.” they said, smiling brightly. Sans relaxed, his eye glowing a little brighter. They kept sitting on that boulder and looked at the sea of lights for who knew how long.

**Notes for the Chapter:**

> Aquamarine actually is the name of a gemstone too! And since they were looking at rocks, I thought that would fit well. It’s a beautiful blue with hints of green. It reminds me of the ocean…
> 
> I will do my best to update regularly. I will also try to make future chapters a bit longer. Kudos and comments certainly help!


	2. Robin Egg

**Notes for the Chapter:**

> This chapter is so goofy. xD I’m sorry about that! I just had way too much fun writing this. Also, those this-does-not-make-sense moments also appear in-game so I think I’m good. 
> 
>  
> 
> Hope you enjoy!

Leaning his chair against the back of the sentry station, Sans enjoyed his time snoozing away again. Even though Papyrus insisted that Sans should work today, there wasn’t much need for the sentry station anymore. Sans decided from the start that capturing the human as something he was not interested in. They were harmless and actually really nice to have around. He guessed that Papyrus still desired to prove to Undyne that he was capable of joining the Royal Guard. In reality, the tall skeleton was very fond of the human as well. Most of us monsters were.

Sans peered at his cell phone to check the time. Usually, his brother would pay him a visit to see if he wasn’t slacking off. Not wanting to disappoint his brother, Sans had actually set an alarm today to at least be awake when Papyrus arrived. But he did not appear. This certainly was a rare occasion. Papyrus was highly dedicated to his schedules. Needless to say, he was only late for legitimate reasons. 

Sans began to grow concerned. Should he go back to Snowdin to check on his brother? In the exceptional case he wouldn’t be able to find Papyrus in town, Sans would have a good excuse to visit Grillby’s. He was getting hungry anyway, since he had already finished his last bottle of ketchup long ago. Sounded like a plan. 

There were some of Papyrus’ puzzles on this route that Sans needed to avoid in order to not mess them up. When he approached them, though, he noticed that the puzzles had not been recalibrated properly. There were footsteps all over in the snow. The taller skeleton always tidied up his puzzles before going to my sentry station. What was going on..? 

“well, since it’s screwed up anyway…” Sans murmured to himself before walking through the maze. The footsteps were sloppy and whoever had been walking around here obviously was not even trying to solve the puzzle.

On closer inspection, Sans found a footprint that was shockingly similar to Papyrus’ boots. The footsteps neatly followed the path to Snowdin, so he would probably find out what was happening soon enough.

And he was right.

Two figures were jumping around in the distance. From what he could hear, saying that one of the two was Papyrus was a pretty safe guess. The other figure was much shorter, even shorter than Sans was. Sans walked closer and realised something… funny was up with Papyrus’ silhouette. 

The pair was running right towards the short skeleton.

“SANS! HELP ME!” Papyrus cried, coming closer at a rapid pace. One of his arms had been completely pulled off by an annoying dog that Papyrus was now chasing. The dog hopped around playfully, while Papyrus’ body looked off-balance. The dog noticed that it was getting awfully close to Sans and headed into a different direction. Sans could have grabbed the arm from the dog’s mouth, but he was laughing too hard to actually do that.

“STOP SLACKING OFF AND HELP ME CAPTURE THAT DOG!” The scarfed skeleton shouted angrily, grabbing Sans along when he passed him. Sans had no choice but to start running as well. 

The dog hopped, jumped and practically flew in all kinds of directions. It often led the skeleton brother into areas filled with pine trees, which made it hard to keep up with the dog. The animal’s movements were swift. Although Papyrus was capable of running fast, he was a turtle compared to the small creature.

After a long while of mindless running, Sans was exhausted. This type of exercise (or exercise at all, rather) was not his specialty. When the three arrived in Snowdin, Sans stopped to catch his breath, bending over and resting his hands on his knees. 

When Sans looked up, Papyrus was still sprinting as fast as ever. No doubt that the dog made not of it as well. Like a cat, it effortlessly jumped up one of the garbage containers and onto the roof of the inn. It turned around and patiently waited for the skeletons to come up. This infuriated Papyrus even further.

“SANS! WE NEED TO GET UP THERE!” he yelled. It took some time before Sans finally caught up with the others. 

“yeah, yeah.” Sans panted breathlessly. In the meantime, Papyrus tried climbing onto the garbage container but that proved to be too unstable for them to stand on.

"LIFT ME UP THE ROOF, SANS!" the taller brother exclaimed. 

“it’s much easier the other way around.” Sans remarked. 

“WHAT A LAZY ATTITUDE, SANS!” Papyrus said, his body still full of adrenaline. Still, he scratched his chin thoughtfully. “BUT… CONSIDERING MY CURRENT ARMLESS STATE, THAT MAY NOT BE A TERRIBLE PLAN AFTER ALL!”

He basically threw his brother up the roof, but since it was covered with a soft snow blanket, it was a soft landing. The dog was long gone. Sans could take his time to help his bother up the house.

“Hey! What do you think you’re doing up there?!” The lady of the inn had come out of the house, obviously not happy about the skeletons and dog hopping on her roof.

Papyrus was the first to come with a reply: “OUR APOLOGIES, MISS! WE’LL BE OFF YOUR ROOF BEFORE YOU KNOW IT!”

“it’s ‘snow’ problem,” Sans added before running away. The back of his head still managed to get slapped by a yet again raging Papyrus. 

The dog had moved to the other side of the roof and the brother initiated the chase. The roofing was slippery, and caused the two to slide and fall repeatedly. Happily nibbling the skeleton arm, the dog was not bothered by this at all.

“GIVE ME MY ARM BACK, YOU FURRY DEMON!”

The white animal jumped to the roof of another building. Without thinking, Papyrus rushed right behind him.

“this is dangerous, pap,” Sans admitted, “it’s better to stay down and wait for the dog instead.”

“NONSENSE! WE ARE TALKING ABOUT MY ARM HERE!” Papyrus said, not looking back.

Although Sans’ opinion of the situation did not change, he really wanted to help his brother out. He really admired Papyrus’ perseverance, after all. Thus, he made a running jump to the other roof. This landing was much more painful than the other one, but they had to keep going. 

The dog leapt from roof to roof and it became increasingly difficult to catch up with it. The three ended up on the roof of Grillby’s. 

‘and i won’t even be able to enjoy a drink while i’m here,” Sans thought to himself. “too bad.”

The next gap was much wider than the ones between the other buildings. The dog made the jump seem easily and he looked back at the brothers, eagerly awaiting them. It was Papyrus’ turn. He barely made it. This concerned Sans, as he knew he certainly wouldn’t make it. On the other hand, he didn’t want to let his brother down. He made a leap of faith.

It went horribly wrong.

The last thing Sans saw was the scared expression of his brother staring at him. He fell fast, and when he hit the ground, his sight turned black.

When he woke up, he realised he was in the comfort of his own room again. The human was sitting on a nearby chair reading a book. They noticed that Sans had woken up and called out: “Pap, he’s awake!”

Shortly after, Sans heard Papyrus coming stomping up the stairs and the door flew open. He was holding a proper breakfast, including milk and a hard-boiled egg. His missing arm was back, so that was great news.

“GREETINGS, BROTHER! HAVE YOU RESTED WELL? HOW ARE YOU FEELING?" Papyrus was his enthusiastic old self again.

“nghh,” Sans barely uttered. His voice was still hoarse. “how long have i been out?”

“Do you really want to know?” the human grinned.

Sans wanted to sit up straight, but a stabbing pain prevented him from moving his torso. His head fell back into his pillow. “nevermind.” 

“YOUR RIB BROKE WHEN YOU FELL.” Sans traces his ribs using his fingers. They were covered in bandage. “YOU ARE ALLOWED TO REST UNTIL YOU HAVE RECOVERED!” Papyrus announced as if it was the most generous thing he’d said in weeks. It made Sans chuckle anyway.

“thanks, bro. so how’d you get your arm back?”

Papyrus explained that he had abruptly ended his chase when he saw that Sans fell down. Together with the help of some bystanders, he was carried back home where he was taken care of by Papyrus and the human, who stayed with the skeletons often. The morning after, a villager was at their door. Papyrus followed the villager to the back of the house. Between the trees, in a wide trench, there was an entire nest that was most likely constructed by the dog.

“IT WAS AN UTMOST ODD SIGHT TOO SEE,” he continued, “THE DOG SEEMINGLY HAD A COLLECTION OF CURIOUS ITEMS. BISICLES, DOORKNOBS, A STRANGE ARTIFACT… EVEN SOME OF GRILLBY’S LIQUOR BOTTLES!”

Sans wondered if they had already given back the liquor to Grillbz or if he just got free booze. 

“MY ARM WAS THERE, TOO! I AM THE GREAT PAPYRUS ONCE AGAIN!” Papyrus called out at a much higher volume than necessary, striking a dramatic pose before he put down the breakfast in front of Sans.

“LOOK, THE EGG I HAVE PREPARED FOR YOU ALSO ORIGINATED FROM THE NEST!”

I frowned at the egg. It had a shade similar to robin egg blue, but its size was quite big. There was something strange about it, though. What was that egg doing in a dog’s nest? Why did the dog even have a nest? Either way, Papyrus seemed to be missing a crucial point.

“hey bro, that’s cruel.” Sans said while poking the egg. It was still fairly warm.

“WHAT IS IT, SANS? AREN’T YOU IMPRESSED BY MY SUPERIOR COOKING SKILLS?” Papyrus sounded slightly disappointed. “THE HUMAN TOLD ME THAT BOILING AN EGG IS A TASTY TREAT.”

“yeah, if it’s not fertilised. you could have been boiling a living thing.”

The human turned pale. They obviously did not pay that in mind. Papyrus stared at him before the realisation hit him and he cried out.

“OH MY GOD! DID I JUST KILL AN INNOCENT BEING? NO!” Papyrus was spinning around in circles. The human tried to calm him down. Since it did not matter much anymore, Sans cracked the egg, slicing it in half with a knife to look inside. False alarm.

"it's okay, folks. i don’t see any boiled bird,” the short skeleton grinned before adding, “or dog.”

It took a while before Papyrus calmed down. The human tried their best to comfort the traumatised monster. In the meantime, Sans was eating the breakfast that was made for him. He couldn’t help making one final comment.

“it’s okay pap,” Sans said, “i must admit that this breakfast is absolutely ‘eggcellent’.”

Papyrus stormed around the room again, this time enraged.

**Notes for the Chapter:**

> Yep, GOOFS. I’m sorry if this was not what you expected it to be but I had a ton of fun writing this chapter! 
> 
> Robin eggs are extremely blue and a shade is even named after the colour of the egg shells! I had never heard of the shade up until a couple of weeks ago when I saw a body paint palette called ‘Robin Egg’. It was very pigmented and it reminded me a bit of another shade, which may also appear later in the story…
> 
> Needless to say, the eggs in the chapter were not actually robin eggs as they're not really edible like chicken eggs. But what kind of eggs were they then..? Ahuhuhu~
> 
> I hope you enjoyed this chapter a little bit! Comments and kudos are always appreciated! Cheers!


End file.
